What are characteristics of sex-linked traits?

Answer 1

Sex-linked traits are usually passed from mother to son by a defective gene on the X chromosome.

Three examples of sex-linked traits are:

• Color blindness
• Hemophilia
• Baldness

Answer 2

Sex-linked traits do not follow the same probability/inheritence patterns in male offspring as they do in female offspring.

Normal inheritance on autosomes where the parents are both heterozygotes the

expected inheritance for both males and females is 1:2:1

Sexlinked recessive traits will only be displayed phenotypically in the female offspring of a carrier female if the father is affected. Female children from a carrier mother and non-affected father will never be phenotypically affected and will be carriers 50% of the time.

Male offspring have a 50% chance of being affected and a 50% chance of genetically free of the disease.

Other sex-linked characteristics, like tortoiseshell coloration in cats are controlled by the random production of bar-bodies (one x-chromosome shutting off randomly in the epidermis during developement, resulting in radom coat color variation.

Male cats cannot display the characteristic because their have only one X chromosome that remains active.